docs: def age_range(self):
          """A tuple of two ints - the minimum and maximum age of the person."""
          if self.date_range is None:
              return None, None
          start_date = DateRange(self.date_range.start, self.date_range.start)
          end_date = DateRange(self.date_range.end, self.date_range.end)
          start_age = DOB(date_range=end_date).age
          end_age = DOB(date_range=start_date).age
          return start_age, end_age